(Beyond Pesticides, October 20, 2011) The Center for Biological Diversity filed a lawsuit yesterday against the Environmental Protection Agency (EPA) and U.S. Fish and Wildlife Service (FWS) for failing to evaluate and act on threats to the threatened California red-legged frog posed by more than 60 toxic pesticides used in and near its habitats. The Center had announced its intent to sue the two agencies back in December 2010.

A 2006 legal settlement secured by the Center requires EPA to assess the impacts of harmful pesticides on red-legged frogs and formally consult with the Fish and Wildlife Service to address those impacts. EPA determined that widespread use of more than 60 pesticides is likely harming red-legged frogs, but since the agency and the Fish and Wildlife Service have failed to complete the required evaluations, no permanent protections for frogs have been put in place.

â€śFederal agencies acknowledge that scores of pesticides may harm Californiaâ€™s rare red-legged frogs, but for years now theyâ€™ve neglected to complete biological evaluations of the effects of these chemicals,â€ť said Jeff Miller, a conservation advocate with the Center. â€śCaliforniaâ€™s imperiled frogs are suffering as a result.â€ť

â€śBiological opinions,â€ť the evaluations required by the Endangered Species Act, would likely restrict pesticide uses in and near frogsâ€™ wetlands habitats and could even result in cancellations of some pesticide registrations. EPA submitted initial assessments of more than 60 registered pesticides between 2007 and 2009, concluding that 62 chemicals are likely to harm red-legged frogs. But the Fish and Wildlife Service asserted the EPA had not provided sufficient information to complete the biological opinions.

The Endangered Species Act requires the EPA to consult with federal wildlife agencies to ensure that the EPA avoids authorizing pesticide uses that jeopardize endangered species. If the Fish and Wildlife Service determines EPA registration of a pesticide is likely to jeopardize listed species, it may specify reasonable and prudent alternatives and suggest use restrictions to avoid adverse effects.

The pesticides of concern for red-legged frogs include several controversial chemicals that public health, food-security, sustainable-farming, and farmworker and conservation groups advocate banning due to unacceptable hazards to humans and wildlife, such as atrazine, chlorpyrifos, endosulfan, methomyl and propargite. Some of the pesticides are known endocrine disruptors, which interfere with natural hormone functions, damage reproductive function and offspring, and cause developmental, neurological, and immune problems in wildlife and humans. For example, the herbicide atrazine has been shown to chemically castrate male frogs even at extremely low concentrations.

Conservation groups have filed a series of lawsuits attempting to force such consultations, primarily in California, which have resulted in interim restrictions on pesticide use near endangered species habitats. The Center filed litigation in 2002 challenging EPA registration and reregistration of pesticides that pose risks to red-legged frogs. The 2006 settlement agreement forced EPA to conduct â€śeffects determinationsâ€ť for these pesticides. The registrations of two chemicals, fenamiphos and molinate, were subsequently cancelled. EPA determined that 64 other pesticides are â€ślikely to adversely affectâ€ť or â€śmay affectâ€ť red-legged frogs. In January 2011, the Center and Pesticide Action Network North America filed the most comprehensive legal action ever brought under the Endangered Species Act to protect imperiled wildlife from pesticides. The suit seeks to compel EPA to evaluate the impacts of hundreds of pesticides known to be toxic to more than 200 endangered and threatened species.

According to the Center, more than 200 million pounds of pesticides are applied each year in California; for most of these chemicals, EPA has not evaluated the impacts on endangered species. Amphibians are declining at alarming rates around the globe, and scientists believe industrial chemicals and pesticides may be partly to blame. Because amphibians breathe through their permeable skin, they are especially vulnerable to chemical contamination. Frog eggs float exposed on the water surface, where pesticides tend to concentrate, and hatched larvae live solely in aquatic environments for five to seven months before they metamorphose, so agricultural pesticides introduced into wetlands, ponds and streams are particularly harmful.

Though at one point they were abundant in California, the red-legged frogs were listed as threatened under the Endangered Species Act in 1996. Their numbers have declined more than 90 percent and, according to the Center, the species is no longer found in 70 percent of its former range.

â€śBecause theyâ€™re so sensitive to chemical contaminants, frogs are an important barometer of the health of our aquatic ecosystems,â€ť said Mr. Miller. â€śPesticides found in red-legged frog habitat can also contaminate our drinking water, food, homes and schools, posing a disturbing health risk.â€ť